Plant of the fern family

ABSTRACT

A new and distinct variety (cultivar) of fern plant of the group known commercially as &#34;Boston ferns&#34; has been discovered and propagated. The new cultivar originated as a vegetative variant (&#34;bud sport&#34;) of a plant of Nephrolepis exaltata cv. Verona, and is distinguished from its parent and other cultivars of &#34;Boston ferns&#34; by fronds that have shorter, more numerous and crowded divisions which grow entangled with one another to produce thick matted blades, and by pinnules that have laminae which are very small, variable in shapes but predominately narrowly linear, irregularly pinnatifid or forked.

This disclosure relates to a population of cultivated fern plantsbelieved to represent a new and distinct type of "Boston fern", andwhich has been named Nephrolepis exaltata cv. Frizzie Lizzie by thediscoverer.

There are many types of "Boston fern" that have been given cultivarnames and known today in the foliage plant market and still others nolonger are recognized to be of commercial value. These all are membersof a variety known to science as Nephrolepis exaltata var. Bostonensisand all are considered to be vegetative variations and descendants of anoriginal fern in the Boston area. These cultivars differ in their growthforms and in the forms of their leaves and leaflets. The originalvariety was and still is a rather coarse fern with leaves once-pinnatelycompound. Today there are dwarf races as well as ones with leaves 3 and4 times compound and some with minute leaflets.

Interest in the new cultivar mainly centers in its repeatedly dissectedleaves with short divisions and small variable laminae and that growinto a dense "fluff" of entangled adjacent leaves. The whole plantbecomes a matted misty green dome that hides its container and makes aninteresting house-plant.

Recognized in April, 1973 growing from a bud on the stolon of cv.Verona, the new shoot appeared in sharp contrast with other parts ofthat plant. Separated from its parent the new plantlet was grown andpropagated in the same greenhouse and has remained stable and unlike theparent cultivar through 10 generations of vegetative propagations.

Currently several dozen plants of the new cultivar are uniform andeasily distinguishable from other types of ferns known to thediscoverer. From ferns which generally resemble it such as cv. Smithii,cv. Fantasia it differs by:

A. Leaves pendant at an earlier age and tending to continue to be bentabaxially.

B. Divisions of the blade crowded into thicker, denser "fluff" entangledwith adjacent leaflets and leaves.

C. Laminae of the young leaf resembling those of cv. Verona but on olderleaves predominantly narrowly linear, irregularly pinnatifid ordichotomously branched.

My new variety is shown in the accompanying color photographic drawingswherein:

FIG. 1 is a side view of a typical specimen growing in a hanging basketand showing tips of a few nearly erect young fronds appearing at the topand a mass of non-erect and generally downwardly bent leaves of whichthe oldest hang close to and completely hide the basket, the basketbeing positioned on a 10 inch diameter clay pot;

FIG. 2 is a similar view of a specimen having a typical moderateyellow-green color of a specimen according to the invention;

FIGS. 3 and 4 are a top or adaxial view and a side or edge view,respectively, of the same single frond showing the delicate andentangled divisions of the leaf blade and of the small ultimatepinnules, and the fluffy matted growth pattern of the repeatedlybranched segments of the leaf, the whole frond shown being approximately20 cm. in length; and

FIG. 5 is a macro-photographic print of small ultimate divisions of aterminal portion of a frond, approximately 4 cm. overall, showingdetails of typical pinnae and pinnules of a specimen of the variety.

DETAILED DESCRIPTION

The following is a description of a plant of the new fern cultivar grownunder usual glass-house care in light approximately 35% of full sunlightat Woodside Fernery, Jacksonville, Fla.

Name: Nephrolepis exaltata cv. Frizzy Lizzy, E. Arnold.

Parentage: Nephrolepis exaltata cv. Verona by vegetative variation("sport").

Classification: Willis, J. C. A Dictionary of Flowering Plants andFerns, 8th ed., 1973, Cambridge Univ. Press.

Division.--Pteridophyta. Class -- Fillicopsida. Sub-class -- Filicidae.Order -- Davalliales. Family -- Oleandraceae. Genus -- Nephrolepis.Species -- exaltata.

GENERAL FORM

Terrestrial, shade tolerant, herbaceous fern plant that is sexuallysterile.

Stems: As in other Boston ferns the stems are of two types. The shortrooted leaf-bearing stems produce the clumps of leaves. These areconnected with one another by the horizontal leafless stolons.

(A) Leaf-bearing stems are erect, partly subterranean, cylindric inshape and usually about 1 cm. long and 1-5 mm. in diameter. Theirsurfaces are nearly covered by minute scales, crowded leaf bases andadventitious roots. Internally the vascular tissues have a dictyostelicarrangement surrounded by parenchyma of about equal amounts. Leaves areproduced acropetally for an undetermined length of time as older leavesdie below.

(B) Stolons are pale green or straw-colored, leafless, flexible, andabout 1 mm. in diameter. Growing from between leaf bases these specialbranches extend horizontally mainly above ground in all directions fromthe parent leafy stem. The surfaces of the stolons contain numerouslanceolate scales that are one cell thick, 1-4 mm. long and usually lessthan 1 mm. wide. Internally the central core of protostelic vasculartissues is surrounded by a narrow cylinder of parenchyma that containsfew chloroplasts. At intervals of about 3-6 cm., buds may appear on thestolon. From these buds are produced new leaf-bearing stems with theirleaves and with adventitious roots anchored in the substrate. These budson the stolons and similar ones produced rarely on leaves and rootsserve as the only natural means of propagating the plant.

LEAVES

(A) General -- A single leaf, or frond, of the new fern consists of aslender stalk, (stipe) and a compound blade made up of a main axis(rachis) to which are attached the compound pinnae that consist ofprimary and secondary axes and their terminal flattened laminae. As inother Boston ferns the blades of the leaves are the principal visibleparts of the plants because they overgrow the stems and lower parts ofthe leaves. Color of the plant is largely that of its leaves, andusually is moderate yellow-green Munsell color hue 5 GY 5/6, but darkershades of green appear after application of nitrogenous fertilizers orwhen the plants are kept heavily shaded. Because growing points occur atthe ends of the rachis and all of its pinnae a leaf is capable ofgrowing very large. However, an optimal size for the new fern leaves isabout 40 cm. in length and 6 cm. in width at the middle of the blade. Atthis size under ordinary greenhouse care some of the older pinnae tendto become yellow and crowded and preferably may be pruned away.

(B) Stipe. The stalk of the frond is slightly flat on its adaxial side,bears numerous scales like those of the stolons, and grows to about 2mm. in diameter and 4 cm. in length. In young leaves the stipe isslender yet rigid enough to hold the blade nearly erect and has the samecolor as the blade. As the blade is enlarged the stipe becomes bentdownward and its color changes to yellow-green, or brownish but itremains flexible.

(C) Rachis. This is the main axis of the blade from its lowest pinna toits growing apex. It is a continuation of the stipe and resembles it inshape and color. Scales on the rachis are fewer toward its apex andshort hairs are more numerous. Along both sides of the rachis the pinnaeare attached alternately and gradually closer together toward the apex.Color of the rachis is the same as that of the adjacent pinnae.

(D) Pinnae. Younger and smaller pinnae are often only once compound, butpinnae that are 10 cm. or more long usually are 3 pinnatifid. The pinnaeand their segments grow at an angle toward the apex of the blade, and atan angle adaxial to the plane of the blade. This tends to establishthickness and fluff to the blade as a whole. The primary and secondaryaxes of the pinnae are essentially branches from the rachis and aresimilar to it in appearance. The closeness of the segments of the pinnaeand their angle of growth cause them to entangle with other segments ofthe same or adjacent pinnae or even adjacent fronds. Generally thesecondary axes of pinnae gradate into the pinnules or into their shortstalked segments and have similar coloration and dermal hairs.

(E) Pinnules. These are the primary divisions of the pinnae. Sizes andforms of the pinnules and shapes of their laminae constitute distinctivefeatures of this new fern. In the original type of Boston fern thepinnae are not divided, and hence the term pinnule does not apply. Inthe new cultivar the pinnae generally are divided sometimes once,usually twice, rarely three times and terminate in flat segments,laminae, that contain veins. Most Boston ferns produce a few foliarsegments that resemble pinnae of the original variety, and must bepruned out to keep a uniform appearance. Such "reversion" segments arerare in the new cultivar.

Larger laminae are about 5mm. wide and up to 12 mm. long. The shorterones are obovate or fan-shaped, while other are lanceolate or nearlylinear. Their margins are crenate or shallowly lobed. Venation of thelarger segments is asymetrically pinnate and open (not netted). Thesingle main vein is non-median, nearer the basiscopic margin, and itspinnately arranged branches usually are once forked and each veinletends in an obvious enlargement close to the margin of the lamina.

Smallest segments of pinnules frequently are only 1 mm. wide and up to20 mm. long and supplied by a single median vein. Some of these narrowlinear laminae are forked or irregularly lobed, in which case each forkor lobe is supplied by a branch vein ending.

Laminae of intermediate sizes are mostly obovate or fan-shaped and havecrenate margins. Their largest dimension generally is 2-8 mm. and theirveinlets are evenly distributed, forked, and without a midrib.

Regardless of size, all pinnules have epidermal hairs distributed alongthe margins of their laminae and on the undersides of veins. Each hairis composed of a tier of 4-6 cells and terminated by a single globosecell that is larger than the diameter of other cells of the hair.Similar hairs occur on other parts of the frond where they may beaccompanied by scales.

Tissue between veins varies in thickness from papery thin andtranslucent in smaller pinnules to thicker and opaque in larger ones.Color hue in pinnules varies with thickness of the laminae so theirnumber and small sizes may cause the lighter color of the new cultivaras compared with many other Boston ferns.

ROOTS

These ferns do not have primary root systems. The adventitious rootsgrow out from the leafy stems and from buds that arise on stolons andelsewhere. The roots are long, slender and sparsely branched. Theydiffer from stolons mainly by their dark brown color, and by theirgrowth into the substrate rather than parallel to its surface.

Roots of the new cultivar are numerous but they seem restricted to theupper few centimeters of soil. By contrast other Boston ferns grown inthe same conditions have deeper root systems.

I claim:
 1. The new and distinct plant variety of Boston fernsubstantially as herein described and characterized by a growth habitwhich provides specimens with repeatedly dissected leaves with shortdivisions and small variable pinnules and that appears as a dense fluffydome-shaped mass of entangled leaves, and that, in comparison toNephrolepis exaltata cv. Smithii and cv. Fantasia, has leaves whichbecome pendant at an earlier age and which tend to continue to be bentabaxially, has divisions of the blade which so crowd into each other andinto adjacent leaflets and leaves as to form a thicker, denser andfluffier mass, and has pinnules with laminae predominantly more narrowlylinear, irregularly pinnatifid or dichotomously branched, the overallcolor of said specimens being substantially moderate yellow green.